Serrated polyps of the colon and rectum:Remove or not?

In recent years,the serrated neoplasia pathway where serrated polyps arise as a colorectal cancer has gained considerable attention as a new carcinogenic pathway.Colorectal serrated polyps are histopathologically classified into hyperplastic polyps(HPs),sessile serrated lesions,and traditional serrated adenomas;in the serrated neoplasia pathway,the latter two are considered to be premalignant.In western countries,all colorectal polyps,including serrated polyps,apart from diminutive rectosigmoid HPs are removed.However,in Asian countries,the treatment strategy for colorectal serrated polyps has remained unestablished.Therefore,in this review,we described the clinicopathological features of colorectal serrated polyps and proposed to remove HPs and sessile serrated lesions≥6 mm in size,and traditional serrated adenomas of any size.

Clinicopathological features and expression of regulatory mechanism of the Wnt signaling pathway in colorectal sessile serrated adenomas/polyps with different syndrome types

BACKGROUND Colorectal cancer(CRC)is the third most common cancer worldwide,with the fourth highest mortality among all cancers.Reportedly,in addition to adenomas,serrated polyps,which account for 15%-30%of CRCs,can also develop into CRCs through the serrated pathway.Sessile serrated adenomas/polyps(SSAs/Ps),a type of serrated polyps,are easily misdiagnosed during endoscopy.AIM To observe the difference in the Wnt signaling pathway expression in SSAs/Ps patients with different syndrome types.METHODS From January 2021 to December 2021,patients with SSAs/Ps were recruited from the Endoscopy Room of Shanghai Traditional Chinese Medicine-Integrated Hospital,affiliated with Shanghai University of Traditional Chinese Medicine.Thirty cases each of large intestine damp-heat(Da-Chang-Shi-Re,DCSR)syndrome and spleen-stomach weakness(Pi-Wei-Xu-Ruo)syndrome were reported.Baseline comparison of the general data,typical tongue coating,colonoscopy findings,and hematoxylin and eosin findings was performed in each group.The expression of the Wnt pathway-related proteins,namelyβ-catenin,adenomatous polyposis coli,and mutated in colorectal cancer,were analyzed using immunohistochemistry.RESULTS Significant differences were observed with respect to the SSAs/Ps size between the two groups of patients with different syndrome types(P=0.001).The other aspects did not differ between the two groups.The Wnt signaling pathway was activated in patients with SSAs/Ps belonging to both groups,which was manifested asβ-catenin protein translocation into the nucleus.However,SSAs/Ps patients with DCSR syndrome had more nucleation,higherβ-catenin expression,and negative regulatory factor(adenomatous polyposis coli and mutated in colorectal cancer)expression(P<0.0001)than SSA/P patients with Pi-Wei-Xu-Ruo syndrome.In addition,the SSA/P size was linearly correlated with the related protein expression.CONCLUSION Patients with DCSR syndrome had a more obvious Wnt signaling pathway activation and a higher risk of carcinogenesis.A high-quality colonoscopic diagnosis was essential.The thorough assessment of clinical diseases can be improved by combining the diseases of Western medicine with the syndromes of traditional Chinese medicine.

Detection Rate, Distribution, Clinical and Pathological Features of Colorectal Serrated Polyps

Background：Colorectal serrated polyp is considered as histologically heterogeneous lesions with malignant potential in western countries.However,few Asian studies have investigated the comprehensive clinical features of serrated polyps in symptomatic populations.The aim of the study was to evaluate the features of colorectal serrated polyps in a Chinese symptomatic population.Methods：Data from all consecutive symptomatic patients were documented from a large colonoscopy database and were analyzed.Chi-square test or Fisher＇s exact test and logistic regression analysis were used for the data processing.Results：A total of 9191 （31.7%） patients were detected with at least one colorectal polyp.The prevalence of serrated polyps was 0.53% （153/28,981）.The proportions of hyperplastic polyp （HP）,sessile serrated adenoma/polyp （SSA/P）,and traditional serrated adenoma （TSA） of all serrated polyps were 41.2%,7.2%,and 51.6%,respectively,which showed a lower proportion of HP and SSA/P and a higher proportion of TSA.Serrated polyps appeared more in males and elder patients while there was no significant difference in the subtype distribution in gender and age.The proportions of large and proximal serrated polyps were 13.7% （21/153） and 46.4% （71/153）,respectively.In total,98.9% （89/90） serrated adenomas were found with dysplasia.Moreover,14 patients with serrated polyps were found with synchronous advanced colorectal neoplasia,and large serrated polyps （LSPs） （odds ratio：3.446,95% confidence interval：1.010-11.750,P 〈 0.05）,especially large HPs,might have an association with synchronous advanced neoplasia （AN）.Conclusions：The overall detection rate ofcolorectal serrated polyps in Chinese symptomatic patient population was low,and distribution pattern of three subtypes is different from previous reports.Moreover,LSPs,especially large HPs,might be associated with an increased risk of synchronous AN.

Correlations of morphology and molecular alterations in traditional serrated adenoma

Traditional serrated adenoma was first reported by Longacre and FenoglioPresier in 1990.Their initial study described main features of this lesion,but the consensus diagnostic criteria were not widely adopted until recently.Traditional serrated adenoma presents with grossly protuberant configuration and pineconelike appearance upon endoscopy.Histologically,it is characterized by ectopic crypt formation,slit-like serration,eosinophilic cytoplasm and pencillate nuclei.Although much is now known about the morphology and molecular changes,the mechanisms underlying the morphological alterations are still not fully understood.Furthermore,the origin of traditional serrated adenoma is not completely known.We review recent studies of the traditional serrated adenoma and provide an overview on current understanding of this rare entity.

Sessile serrated adenomas:Demographic,endoscopic and pathological characteristics

AIM:To study the demographic and endoscopic characteristics of patients with sessile serrated adenoma(SSA) in a single center.METHODS:Patients with SSA were identified by review of the pathology database of Mayo Clinic Arizona from 2005 to 2007.A retrospective chart review was performed to extract data on demographics,polyp characteristics,presence of synchronous adenomatous polyps or cancer,polypectomy methods,and related complications.RESULTS:One hundred and seventy-one(2.9%) of all patients undergoing colonoscopy had a total of 226 SSAs.The mean(SE) size of the SSAs was 8.1(0.4) mm;42% of SSAs were ≤ 5 mm,and 69% were ≤ 9 mm.Fifty-one per cent of SSAs were located in the cecum or ascending colon.Approximately half of the patients had synchronous polyps of other histological types,including hyperplastic and adenomatous polyps.Synchronous adenocarcinoma was present in seven(4%) cases.Ninety-seven percent of polyps were removed by colonoscopy.CONCLUSION:Among patients with colon polyps,2.9% were found to have SSAs.Most of the SSAs were located in the right side and were safely managed by colonoscopy.

Brown slits for colorectal adenoma crypts on conventional magnifying endoscopy with narrow band imaging using the X1 system

BACKGROUND Accurate diagnosis of colorectal premalignant polyps,including adenomas,is vital in clinical practice.AIM To investigate the diagnostic yields of novel findings of brown slits for adenomas.METHODS Patients who underwent colonoscopy at the Toyoshima Endoscopy Clinic were enrolled.Polyps sized≥5 mm suspected of adenomas or clinically significant serrated polyps were included in the study.We defined the surface structures of colorectal polyps,which were brown curves inside and along the tubular glands identified using a combination of a new X1 system(Olympus Corporation)and a conventional magnifying colonoscope with non-staining narrow band imaging(NBI),as brown slits.The brown slits corresponded to slit-like lumens on endocytoscopy and histological crypt openings of an adenoma.We evaluated the diagnostic performance of brown slits for adenoma.RESULTS A total of 108 Lesions from 62 patients were eligible.The average age was 60.4 years and 41.9%were male.The mean polyp size was 7.45±2.83 mm.Fifty-seven lesions were positive for brown slits.Histopathological diagnosis comprised 59 low-grade tubular adenomas,16 sessile serrated lesions,and 33 hyperplastic polyps.Among 59 adenomas,56(94.9%)were positive for brown slits.Among 16 sessile serrated lesions,0(0%)was positive for brown slits.Among 33 hyperplastic polyps,1(3.0%)was positive for brown slits.The sensitivity,specificity,and accuracy of brown slits for adenoma were 94.9%,98.0%,and 96.3%,respectively.The positive predictive value and negative predictive value of brown slits for adenoma were also excellent for 98.2%,and 94.1%,respectively.CONCLUSION Brown slits on conventional magnifying endoscopy with non-staining NBI using the X1 system were useful for diagnosing colorectal adenoma.The new endoscopy system could be examined using new standards.

Impact of looping on premalignant polyp detection during colonoscopy

BACKGROUND The presence of premalignant polyps on colonoscopy is an indicator of metachronous colorectal cancer.Looping during colonoscopy is associated with old age,female sex,and colonoscopy insertion time.However,the clinical significance of looping is not fully understood.We aimed to clarify the effect of looping on colorectal premalignant polyp detection.AIM To assess the effects of looping on premalignant polyp detection using logistic regression analyses.METHODS We retrospectively investigated patients who underwent colonoscopy at Toyoshima Endoscopy Clinic between May,2017 and October,2020.From the clinic’s endoscopy database,we extracted data on patient age,sex,endoscopist-assessed looping,colonoscopy duration,endoscopist experience,detection rate,and number of premalignant polyps.RESULTS We assessed 12259 patients(mean age,53.6 years;men,50.7%).Looping occurred in 54.3%of the patients.Mild and severe looping were noted in 4399 and 2253 patients,respectively.The detection rates of adenomas,advanced adenomas,high-risk adenomas,clinically significant serrated polyps(CSSPs),and sessile serrated lesions(SSLs)were 44.7%,2.0%,9.9%,8.9%and 3.5%,respectively.The mean numbers of adenomas and SSLs were 0.82 and 0.04,respectively.The detection rates of adenomas,high-risk adenomas,and CSSPs increased with looping severity(all P<0.001).The number of adenomas increased with looping severity(P<0.001).Multivariate analyses found that detection of adenomas,high-risk adenomas,and CSSPs was associated with severe looping(P<0.001,P<0.001,and P=0.007,respectively)regardless of age,sex,time required for colonoscope insertion and withdrawal,and endoscopist experience.CONCLUSION Looping severity was independently associated with high detection rates of premalignant polyps.Therefore,looping may predict the risk of metachronous colorectal cancer.Endoscopists should carefully examine the colorectum of patients with looping.

Risk factors for recurrence of colorectal conventional adenoma and serrated polyp

Background Removal of colorectal polyps during screening could reduce the incidence of colorectal cancer(CRC).However,there is a lack of data on risk factors associated with recurrence of polyps,including conventional adenomas and serrated polyps(SPs).This study aimed to determine risk factors for recurrence of colorectal polyps and their subtypes based on the characteristics of the patients and polyps.Methods A total of 1,165 patients diagnosed with conventional adenoma or SP in the Sixth Affiliated Hospital of Sun Yat-sen University between January 2013 and December 2019 were enrolled in this study,including 668 cases with conventional adenomas,385 with SPs,and 112 with coexistence of adenomas and SPs.Univariate analysis and multivariate logistic regression were used to identify potential risk factors for polyp recurrence.A nomogram was established according to risk factors and the performance was evaluated using calibration plots.Results During a median follow-up of 24 months,recurrent polyps were observed in 531(45.6%)cases.Male,age≥50 years,body mass index(BMI)≥24 kg/m^(2),at least three polyps,smoking,alcohol consumption,family history of polyps,and family history of CRC were independent risk factors for polyp recurrence.The Harrell’s C-index of the nomogram developed with these parameters was 0.69 and the calibration plots showed good agreement between actual polyp recurrence and nomogram-predicted recurrence probability.In the subtype analyses,conventional adenomas had the same risk factors for recurrence as all polyps,while smoking,alcohol consumption,family history of polyps,and family history of CRC were not risk factors for SP recurrence.Conclusions We identified several risk factors for recurrence of colorectal polyps and found that some of them could increase the risk of adenoma recurrence but not SP recurrence,including smoking,alcohol consumption,and family history of polyps/CRC,which might help us to understand different etiology and biology between conventional adenomas and SPs.